1. Field of the Invention
This invention relates to a process for the manufacture of a rough-shaped, cold-rolled cladding tube of zirconium alloy.
2. Discussion of the Background
It is known that a "Zircaloy 2" or "Zircaloy 4" ingot (classified according to the ASTM-B352 specification "grades" R 60802 and R 60804) can be transformed by hot-working either completely in the .beta. range at a temperature of from 900.degree. to 1040.degree. C., or completely in the .alpha. range, typically at temperatures of from 700.degree. to 790.degree. C. After hot-working, billets cut out of the rolled bar or bars are quenched in water after preheating in the .beta. range, and are then extruded in the .alpha. range in the form of hollow rough shapes. These extruded hollow rough shapes are then subjected to a surface treatment followed by cold-rolling and one or more reheating treatments in the range and are thereby converted into cold-rolled, rough-shaped cladding tubes.
These cold-rolled shapes are then again rolled in the cold in several passes and heat-treated to give cladding tubes. When the hot-working is carried out in the .beta. range, rolling can be effected much more rapidly than in the .alpha. range. The present invention relates to increasing the suitability of these cold-rolled, rough-shapes to be re-rolled in the cold, while preserving at least part of the hot-working in the .beta. range.